emitting objects in the exact same spot
I think the trick to this is to correctly calculate how many frames you have, divide it by the number of particles you want to spawn in your frame rate. 

In the below example I have my end time at 100 frames with 10 particles so it would spawn every 10 frames and a lifetime of 100. You will need to change these numbers based on how many frames you have in your animation. 

 

I also just used a plane for my particle system (no subdivision) and made it smaller than my object that it was spawning. So it mostly comes out at the exact same spot. 



Maybe somebody could come up with a better answer that is easier to control. 

Probably animation nodes would be perfect for this. I just dont know it well enough.